I looked at the map of 192 (which is also called Irlo Bronson Memorial Highway). if you go I-4 get off 192 so that you are heading towards medieval times and arabian nights, mile marker numbers going up. I don't remember if it is west or east. If you begin going the wrong way it is very easy to turn around. You are between mile marker 7 and 8 at this intersection.
Walmart is right past medieval times which is at mile marker 14 (not 11 like I posted incorrectly). It is on the same side as medieval times (which is on the right). There is another walmart on sand lake road but this one is closer to Universal not disney. 192 does get congested. There is also a publix which is on the way to walmart on 192 but it would be on your left side very close to the I-4/192 intersection.